1. Field of the Invention
This invention relates generally to shaft bushings, and more particularly to an improved bushing providing a means for positioning a beating and for providing improved lubricating to the bearing.
2. Description of Related Art
Invention and use of bushing devices is known to the public, as they are commonly used in mechanical assemblies where it is desired to support shafts and to provide improved lubrication thereto. Sugimoto et al U.S. Pat. No. 4,090,748 teaches a device for lubricating a rear bushing in an extension housing of an automotive transmission. Oil grooves which are formed in the bore of a hollow rear bushing are provided in such a pattern that upon rotation of the output shaft, lubricating oil is drawn into the grooves from both the front and rear ends of the bushing. The oil drawn in is distributed over the whole inner surface of the bore and discharged into the space behind the rear bushing. The extension housing is provided with a passageway which interconnects the space behind the rear bushing with the space ahead of it. Allen et al U.S. Pat. No. 4,218,933 teaches a rack and pinion bear assembly which includes a resilient bushing which urges the rack into mesh engagement with the pinion. An arcuate inside bearing surface of the busing has a larger radius of curvature than the curved outside surface of the rack against which it bears. The rack thus makes tangent contact with the bushing. When one portion of the bushing is worn so that excessive play appears in the steering gear assembly, the bushing may be removed from the housing of the assembly and rotated 180 degrees, reinserted into the housing to provide an upward bearing surface for slidably engaging the rack. Harris U.S. Pat. No. 4,189,985 defines a fabric-lined epoxy resin cylinder with lubricant retaining grooves. A woven seamless sleeve including axial yarns from the inner face of an epoxy resin cylinder for an air operated linear actuator. Under certain conditions, a minute internal, spiral groove develops in applying the resin. In the operation of the actuator the groove serves to retain lubricant. Steiner et al U.S. Pat. No. 4,576,488 shows a bearing busing for journal beating of a brake shaft of a drum brake. One end of the busing on the outside, is provided with a circumferential annular grease recess for the introduction of grease. Branching off in the axial direction from this recess are distributing channels, and disposed as extensions thereof on the opposite axial direction. In order to improve the distribution of grease, and to improve the formation of a closed lubrication film, each distribution channel opens out into a hole, which are interconnected on the inside by a circumferential, first annular channel. The inner lubricating channels are disposed between the distributing channels, extend parallel thereto between the holes and are connected to the first annular channel. The lubricating channels open out into a circumferential second annular channel, which is connected to a least one outlet channel. Mori U.S. Pat. No. 4,655,615 teaches a wrapped cylindrical bushing adapted to be force fitted into an axial opening of a bearing housing and is formed at its outer peripheral surface with one or more oil grooves. The oil groove or grooves are formed by press work such as embossing to extend obliquely relative to a parallel to the axis of the wrapped bushing such that they are in parallel with each other with respect to the line. Upon wrapping a metal strip into the bushing, the small grooves neither lessen the effect due to interference on the wrapped bushing nor produce any craze or crack at or near the oil grooves, thereby attaining out of roundness to a desired extent. Arlott et al U.S. Pat. No. 4,810,105 shows bearing sleeve provided which comprises another shell of a marine brass and an inner lining of nitrile rubber bonded to the inside surface of the shell. The lining extends axially beyond the end of the shell to form a portion positioned beyond the end of the shell and turned over the end of the shell. This portion comprises radial lands separated by radial grooves, and the radial lands define axial bearing surfaces for cooperation with an axial bearing surface of a bearing member which the bearing sleeve surrounds in use.
The prior art does not teach a bushing capable of direct, two-direction lubrication of a type that is inexpensive to manufacture and is essentially clog resistant. The present invention fulfills these needs and provides further related advantages as described in the following summary.